Dietary Brussels Sprouts And Glucosinolate Influence On , Rat Hepatic Polysubstrate Monoxygenases

Summary

Brussels sprouts, fed at 20 per cent of a purified diet to male, weanling SpragueDawleyrats for 24 days, enhanced hepatic polysubstrate monooxygenase (PSM)activities, ie aminopyrine N-demethylase and aryl hydrocarbon hydroxylase, aswell as cytochrome P-450, microsomal protein, and NADPH cytochrome C reductase.A lowered activity of P-nitroanisole O-demethylase occurred. Feeding thesame amount of indole-3-carbinol (IC) or allyl isothiocyanate (AITC) to two othergroups of rats, comparable to the intake of Brussels sprouts, showed similar inductionwith the former, but no induction with the latter compound. AITC and ICare metabolites of glucosinolates that are present in brussels sprou ts as well asother Cruczferae vegetables. Feeding a Brussels-sprouts-residue diet devoid ofglucosinolates showed no enhancement in hepatic aryl hydrocarbon hydroxylase,and NADPI-1 cytochrome C reductase activ ities or cy tochrome P-450 content, butdid induce both O- and N-demethylase activiti es . Thus, Cruczferae vegetables,that have been shown to protect against chemical carcinogenesis in rats via ICenhancing PSM metabolism, contain non-glucosinolate compounds that can alsoinduce these microsomal enzymes.